In the summer of 2009 the Health Research Board published two papers in its Trends Series, one on problem cocaine use1 and one on problem opiate use.2 The papers are based on data reported to the National Drug Treatment Reporting System (NDTRS). It is important to note that the NDTRS collects data on episodes of treatment, rather than the number of individual people treated each year. This means that individuals may appear more than once if they attend more than one treatment service in a year, and may reappear in subsequent years.  

The main findings of the paper on treated problem cocaine use are:

• One-fifth (10,764) of all cases treated for problem drug use between 2002 and 2007, reported cocaine as a problem substance. The annual number of cocaine cases increased by 177%, from 954 in 2002 to 2,643 in 2007. This increase was in line with increases in cocaine seizures, cocaine use among the general population and cocaine-related deaths during the same time period.
• The number of cases who reported cocaine as their main problem drug increased by 502%, from 128 in 2002 to 770 in 2007. The number of cases who reported cocaine as an additional problem drug increased by 128%, from 826 in 2002 to 1,885 in 2007.
• The higher rates of new cases treated for cocaine as their main problem drug were in the north-eastern, south eastern and southern counties.  The incidence of treated problem cocaine use was lower than expected in Dublin due to the fact than many problem cocaine users in Dublin also used opiates, and the opiate was categorised as their main problem drug while cocaine was categorised as an additional problem drug.
• Almost four out of five cases who reported cocaine as their main problem drug used more than one drug. Cocaine was used alongside opiates, cannabis, alcohol and ecstasy.
• There appears to be two profiles of cocaine user entering treatment, those who use opiates alongside cocaine and those who use combinations of alcohol, cannabis and/or ecstasy alongside cocaine.
• The majority of cases who reported cocaine as their main problem drug used it on two to six days per week, indicating that cocaine may be used as a week-end drug or during a binge.
• Half of the cases were under 27 years old, 83% were men and 33% were employed. The proportion of treated cocaine cases in employment was higher than the proportion of opiate cases in employment, 35% versus 13%, indicating that treated cocaine users were from a mix of social backgrounds.
• The majority (69%) of cases were treated in outpatient services in 2007.
• There is a wide variety of interventions provided to cocaine cases, though until there is national data on treatment outcomes it is difficult to comment on the effectiveness of these interventions.  

The main findings of the paper on treated problem opiate use are:

• In total, 11,392 cases were treated for problem opiate (mainly heroin) use in 2007. The number of cases who reported an opiate as a problem drug increased by 29%, from 8,804 in 2002 to 11,392 in 2007. This increase in treatment provision is explained by a combination of factors, an increase in the number of treatment places, an increase in opiate use among the population and an increase in reporting to the NDTRS.
• This increase in treated problem opiate use was in line with increases in heroin seizures in 2005 and 2006, problem opiate use among the population and heroin-related deaths during the same time period.
• The rate of increase in new opiate cases was highest outside Dublin, and in particular in the midland, north eastern, and south eastern counties.
• The proportion of cases treated for opiates as a main problem drug who reported use of more than one drug decreased from 69% in 2002 to 63% in 2007. Between 2002 and 2007, cannabis, benzodiazepines and, in more recent years, cocaine were the most common additional problem drugs used alongside opiates. The use of additional drugs alongside opiates makes it more difficult to treat the addiction successfully.
• Of the 3,575 cases who entered treatment and reported opiates as their main problem drug in 2007, 52% smoked it, 40% injected it, and 4% consumed it orally.
• Between 2003 and 2007 decreasing proportions of cases reported that injecting was their primary route of administration, while correspondingly increasing proportions reported smoking opiates. This is a good news story indicating that harm reduction messages are being implemented and the transmission of blood-borne viruses will be reduced among this cohort.
• The majority of cases who reported an opiate as their main problem drug used it daily, indicating the addictive nature of the drug.
• In 2007, the vast majority (75%) of opiate cases entering treatment were cared for in outpatient services.
• There is a wide variety of interventions provided to opiate cases including counselling, methadone maintenance, brief intervention, and medically assisted opiate detoxification.

These Trends Series papers are available online at www.hrb.ie/health-information-in-house-research/alcohol-drugs/publications/ 

1. Bellerose D, Carew AM, Lyons S and Long J (2009) Trends in treated problem cocaine use in Ireland 2002–2007. HRB Trends Series 6.  Dublin: Health Research Board.
2. Carew AM, Bellerose D, Lyons S and Long J (2009) Trends in treated problem opiate use in Ireland 2002–2007.  HRB Trends Series 7. Dublin: Health Research Board.